1. Field of the Invention
The present invention relates to a power divider and a radio-frequency device, and more particularly, to a power divider and a radio-frequency device capable of enhancing performance of the array antenna and effectively minimizing required area.
2. Description of the Prior Art
An array antenna is an antenna system composed of a plurality of identical antennas arranged in accordance with a specific rule, and has been widely used in a radar system, such as a millimeter-wave or micrometer-wave radar system. In order to achieve specific radiation patterns or satisfy specific weighting among the antennas in the array antenna, the prior art adds filters concatenated to input terminals of the array antenna, which serve as a power divider for achieving required amplitude and phase of each radiation entity. In general, the array antenna and the power divider are individually designed and then directly concatenated; therefore, the array antenna and the power divider of the prior art can hardly be integrated efficiently. Moreover, impedance matching issues must be taken into account as well. Although an additional designed matching circuit may alleviate mismatch and improve performance, price is quite high—for example, area increases, cost rises and antenna gain is reduced, thereby shortening radar detecting distance and limiting scanning angle.
Therefore, enhancing performance of the array antenna and effectively minimizing required area at the same time is a significant objective in the field.